(clock -> clock_core in caravel_clocking, VPWR -> vccd_core and
VGND -> vssd_core in the instances of modules that were pulled from
the management SoC to the top level).
longer in the PDK but have been folded into larger library files.
With the most recent push to open_pdks to fix an error in the I/O
verilog library, the verilog testbenches once again pass.
deleted "resetb_core_h" port label. Corrected the chip_io and chip_io_alt
verilog RTL files to replace the user area power supply clamp cells with
the new clamped3 cell from open_pdks.
three parameterized values used in the RTL verilog. Modified the
"user_defines.v" file to create verilog definitions that match the C-style
definitions from "defs.h", for convenience/simplicity.
fixed by moving from after the managment protect to before it, but
an inversion of the signal was missed, leading to an incorrect
wb_rst_i passed to housekeeping. (2) Revised the method to load
the serial GPIO data chain from a 2-pin, I2C-like method to a
more straightforward 3-pin method with separate reset, clock, and
load pins. The load pin propagates through the chaing like the
other two. Added a bit-bang signal for the load signal as well.
(3) Added an implied buffer after the data output of the GPIO
control block to ensure that the data arrives at the next control
block after the clock, to prevent hold violations.
incorrectly assigned to the clock on the user side of the managment
protect block, causing it to be undefined when the user area power
supply is down. The "hkspi_power" testbench which tests using the
housekeeping SPI while the user area power is grounded now works
correctly.
around the entire padframe. The vccd1 and vccd2 domains are local
to their respective pads, and any bus routing must be done inside
the padframe. This means that all pads operate on global vddio for
3.3V as before, but also global vccd for 1.8V. The user 1.8V voltage
domain only goes as far as the input to the GPIO control block.
to areas not part of the management SoC, including chip_io,
mgmt_protect, and mprj_ctrl and sysctrl_wb (which are now part of
housekeeping). The two housekeeping tests fail and need to be
debugged.
management SoC to the management protect block, and updated the
documentation to include the new wishbone interface for those
signals, and the additional signals on the management SoC pinout.
an unconnected wishbone bus (unconnected inputs). Added the missing
signals for the user IRQ enables to management protect (which have
to come from the management SoC).
implement the arbitration between SPI and back-door. The back-door
access flags when it is going to do a read or write, and the SPI
can have an invalid read or fail a write if the SPI is too fast,
but the wishbone access should be valid. As long as the SPI is
much slower than the core clock (say, 1MHz) then there should be no
contention, which means that contention can always be avoided simply
by slowing the SPI signaling down.
status) so that between rdstb and wrstb, the SPI signals when it is
about to read or write a byte. The back-door wishbone interface then
stalls the CPU during these periods. That allows the CPU to continue
running while the SPI is being accessed without data collisions and
without having to stall for the entire time CSB is held low.
Because SCK is asynchronous to the clock, rare collisions are still
possible; this is not expected to be an issue but might be worth
investigating.
via programming. The values for each of the GPIOs at power-up are
defined in the "user_defines.v" file. For the verilog, they are
applied as parameters. For the layout, they will need to be
separately defined cells for each of the GPIOs, or at least for
each set of unique default values.
since the original one was folded into the sysctrl testbench, but that
testbench no longer uses the SPI master. Moved the SPI master from being
an overlay of the housekeeping SPI to occupying GPIO pins 32 to 35.
Made GPIO 35 a bidirectional pin like 36 and 37 so that the output enable
from the SPI master can be used.
storage. Not all of these pass simulation checks. Added back the
bit-bang control of the GPIO programming. Added back the read-only
interface between the housekeeping module and the SRAM 2nd port.
Revised the memory map text document to reflect the addition of the
SRAM ports. There is not yet a testbench for the SRAM read-only
interface.
Tim Edwards
manarabdelaty